The present invention relates in general to rotary torque transmitting devices and in particular to an improved spring damper arrangement for use in a clutch driven disc assembly.
In most passenger cars and trucks, objectionable vibrations may be generated in the vehicle drive line at certain speeds and load conditions. Some of these disturbances may be eliminated, or reduced to an acceptable level, by incorporating a torsional damper in the driven disc assembly of the vehicle clutch. Typically, such dampers include a plurality of circumferentially spaced coiled springs operatively connected between two relatively rotatable elements of the clutch driven disc assembly.
Clutches having dampers similar to that described above are widely used in vehicular rotary torque transmitting systems. Usually, the two elements of the clutch driven disc assembly are permitted to rotate relative to each other by a relatively small amplitude, approximately ten degrees or less. In such situations, conventional dampers have been found to operate sufficiently well. In certain applications, however, the two elements may be permitted to rotate relative to each other by a relatively large amplitude, up to twenty degrees or more. In dampers which permit such relatively high amplitudes of rotational displacement, proper positioning of the circumferentially spaced springs has been found to be more difficult to achieve and maintain. Improper spring positioning in such a damper can result in undue stress on the springs and spring engaging surfaces which, in turn, can cause premature damper failure.